Interlocking element for a concealed slide fastener



Feb. 25, 1964 IKUO TAKAMATSU 3,121,928

INTERLOCKING ELEMENT FOR A CONCEALED SLIDE FASTENER Filed June 27, 1961FIG. 2

United States Patent 3,121,923 INTERLGCKING ELEMENT FOR A CQNCEALEDSLEDE FASTENER Ikuo Takamatsu, Uozn-shi, Japan, assignor to YoshidaKogyo K.K., Tokyo, Japan, a corporation of Japan Filed June 27, 1%1,Ser. No. 11%,938 Cla ms priority, application Japan Nov. 26, 1960 4-Qlaims. (Cl. 24--2t 5.1)

The present invention relates to interlocking elements for concealedslide fasteners and has for its object to provide improved interlockingelements of the kind which enable smooth operation of a slider memberfor opening and closing the slide fastener, eliminating any danger ofbinding or jamming trouble of the slider member during operation.

In operation of conventional slide fasteners and particularly those ofthe concealed type, the slider member has often been subject to suchtrouble rendering the operation of the slide fastener diflicult or evencompletely impossible. This deficiency of previous concealed slidefasteners has effectively been overcome by the present invention as willbe made apparent hereinafter.

Description will now be made with reference to the accompanying drawingsin which:

FIG. 1 is a perspective view of an embodiment of the interlockingelement according to the present invention;

FIG. 2 is a fragmentary transverse cross section of a concealed slidefastener fitted with interlocking elements one of which is shown in FIG.1, taken through a slider member interengaging the interlocking elementson cooperating fastener strips of the slide fastener; and

FIG. 3 is a perspective View of the concealed slide fastener attached toa fabric cloth and shown in closed state.

With concealed slide fasteners, the interlocking elements are set in arow along the folded braided edges of the respective base strips of theslide fastener. A slider member slidably embraces opposing interlockingelements. Usually, the body of the slider member has its opposite edgeportions extending toward each other along the respective base stripssecured to a fabric. Such edge portions are each more or less jammedbetween the adjacent row of interlocking elements on one hand and theassociated base strip integral with the folded fabric edge on the otherhand. Such slider member cannot be operated smoothly, as will be readilyunderstood. This is particularly true when the fabric carrying the slidefastener has an overlapped joint perpendicular to the length thereof,for example as illustrated in FIG. 3. In case where the slide fasteneris secured to a thick fabric or the row of interlocking elements isarranged to extend in a curved line according to the configuration of agarment or the like, operation of the slider member has been extremelydiflicult and sometimes completely impossible.

Referring now particularly to FIG. 3, there is shown a concealed slidefastener which is stitched onto a fabric 5 along the adjoining edgesthereof which are each folded back on themselves. The slide fastenercomprises a pair of base strips or fastener tapes 4, a pair of rows 9 ofinterlocking elements formed according to the present invention andsecured to the bent edge of the respective base tapes 4, and a slidermember such as indicated at 7 in FIG. 2 (not shown in FIG. 3). Theinterlockng elements 1 each comprise a stem portion In, an interengagingtooth portion 1b and an arcuately curved leg portion 2 integraltherewith that firmly embraces a core braid 8 formed along the extremeedge of the associated base strip 4 as shown in FIG. 2. According to theinvention the outer surface of the arcuately curved leg porton 2 definesa smooth curve and at the free extremity of the curved leg portion 2 anintegral projection 3 is formed extending a substantial distanceoutwardly and substantially perpendicularly to the general plane of thebase strip 4 and terminating in a rounded outer end as shown in FIG. 2.

The slider member 7, as shown in cross section in FIG. 2, has itsopposite edge portions 6 interposed between the row 9 of theinterlocking elements 1 and the associated base strip 4, as with any or"conventional concealed slide fastener and has its inner surface definedby angularly intersecting linear surfaces. It will also be observed,however, that the outwardly extending projection 3 on each of theinterlocking elements defines a space C between the upper surface, asviewed in FIG. 2, of the row 9 of interlocking elements 1 and the lowersurface of the associated base strip 4 along the entire length of therow 9 of the interlocking elements. It will be appreciated that thespace C forms a clearance or passageway through which the convexlycurved outer surface of the adjacent edge portion 6 of the slider member'7 can pass freely thereby ensuring free and smooth sliding movement ofthe slider member over the mating rows 9 of interlocking elements evenwhere the fabric 5 is thick or the rows 9 of interlocking elementsextend in a curved line conforming to the configuration of fabricgarment or the like to which the slide fastener is secured, irrespectiveof whether the fabric has an overlapped joint extending perpendicularlyto the length of the slide fastener as indicated at 10 in FIG. 3 or not.With such jointed fabric, it will be seen that the slide fastener hasits rows 9 of interlocking elements juxtaposed to six plies of fabricover the width B of the joint 10. It is very importarit that withprojections 3 formed on respective interlocking elements 1 of the slidefastener the slider member can be operated smoothly lengthwise of theslide fastener not only over the extent A which is free of such joint1-9 but also over the extent B corresponding to the width thereof.Furthermore, as will readily be observed in FIG. 2, the interlockingelement is so dimensioned relative to the slider member '7 that theprojection 3 is engaged by the adjacent edge portion 6 of the slidermember to serve as a guide therefor in sliding movement thereof enablingfree and smooth operation of the slider member together with theformation of said space be tween the interlocking element and the basestrip.

The present invention thus provides interlocking elements for slidefasteners which enable smooth and light operation of the slider memberat all times completely eliminating any jamming or like trouble involvedwith concealed slide fasteners having conventional interlocking elementswhile at the same time making it possible freely to use a concealedslide fastener with thicker fabrics or curved portions of a garment orthe like.

What is claimed is:

1. In a concealed slide fastener comprising a pair of flexible basestrips, a plurality of interlocking elements disposed along an edge ofeach of said strips and a slider for engaging and disengaging theinterlocking elements on one strip with those on the other, theimprovement comprising each of said elements being generally J-shapedwith a stern portion, an integral interengaging tooth portion at one endof said stem portion and an integral curved leg portion at the oppositeend of the stem portion, said leg portion curving back over said stemportion and gripping an edge portion of the respective base stripbetween said leg portion and stem portion, said leg por tion beingformed at its free end with an integral bulbous head portion ofapproximately elliptical shape with its major axis disposed transverselyof the adjacent part of said leg portion and with an outer portionextending outwardly from said leg in a direction away from said sternportion and having a rounded surface over which said base strip is bent,said outer portion positioning a body portion of said base strip awayfrom the outer surface of said leg portion to provide a predeterminedspace for the free sliding movement of said slider.

2. A concealed slide fastener comprising a pair of flexible base strips,a plurality of interlocking elements disposed along an edge of each ofsaid strips and a slider for engaging and disengaging the interlockingelements on one strip with those on the other strip, each of saidelements being generally J-shaped with a stem portion, an integralinterengaging tooth portion at one end of said stem portion and anintegral curved leg portion at the opposite end of said stem portion,said leg portion curving back over said stem portion and gripping anedge portion of the respective base strip between said leg portion andstem portion, said leg portion being formed at its free end with anintegral enlarged head portion of approximately elliptical shape withits major axis disposed transversely of the adjacent part of said legportion and with an outer portion which extends outwardly from said legin a direction away from said stem portion and has a side surfaceapproximately perpendicular to the adjacent part of said leg and arounded outer surface over which said base strip is bent, said head portion spacing a body portion of said base strip away from the outersurface of said leg portion to provide a predetermined space to receivea portion of said slider which extends around said element and engagessaid side surface of said head portion.

3. In a concealed slide fastener comprising a pair of flexible basestrips, a plurality of interlocking elements disposed along an edge ofeach of said strips and a slider for engaging and disengaging theinterlocking elements on one strip with those on the other, theimprovement comprising each of said elements being generally J-shapedwith a stem portion, an integral interengaging tooth portion at one endof said stem portion and an integral curved leg portion curving backover said stem portion and gripping an edge portion of the respectivebase strip between said leg portion and stem portion, said leg portionbeing formed at its free end with an enlarged head of approximatelyelliptical shape with its major axis disposed transversely of theadjacent part of said leg portion and having a smaller inner portionprojecting inwardly toward said stem portion and coacting with saidstern portion to grip said edge portion of the base strip securely and alarger outer portion extending outwardly from said leg in a directionaway from said stem portion and having a side surface approximatelyperpendicular to the adjacent part of said leg and a curved outersurface over which said base strip is flexed so that a body portion ofsaid base strip is approximately parallel to said stern portion, saidouter portion of said head spacing said body portion of the base stripaway from the outer surface of said leg portion to provide apredetermined space for free movement of said slider.

4. A concealed slide fastener according to claim 3, in which said edgeportion of the base strip which is gripped between said curved legportions and stem portions of said interlocking elements comprises acore braid formed along the extreme edge of said base strip.

References Cited in the file of this patent UNITED STATES PATENTS2,068,939 Winterhalter Jan. 26, 1937 2,263,651 Silberman Nov. 25, 19412,888,727 Heimberger June 2, 1959 2,991,527 McNamara June 11, 1961FOREIGN PATENTS 489,657 Great Britain Aug. 2, 1938 1,035,786 France Aug.31, 1953 201,777 Australia July 16, 1959

1. IN A CONCEALED SLIDE FASTENER COMPRISING A PAIR OF FLEXIBLE BASESTRIPS, A PLURALITY OF INTERLOCKING ELEMENTS DISPOSED ALONG AN EDGE OFEACH OF SAID STRIPS AND A SLIDER FOR ENGAGING AND DISENGAGING THEINTERLOCKING ELEMENTS ON ONE STRIP WITH THOSE ON THE OTHER, THEIMPROVEMENT COMPRISING EACH OF SAID ELEMENTS BEING GENERALLY J-SHAPEDWITH A STEM PORTION, AN INTEGRAL INTERENGAGING TOOTH PORTION AT ONE ENDOF SAID STEM PORTION AND AN INTEGRAL CURVED LEG PORTION AT THE OPPOSITEEND OF THE STEM PORTION, SAID LEG PORTION CURVING BACK OVER SAID STEMPORTION AND GRIPPING AN EDGE PORTION OF THE RESPECTIVE BASE STRIPBETWEEN SAID LEG PORTION AND STEM PORTION, SAID LEG PORTION BEING FORMEDAT ITS FREE END WITH AN INTEGRAL BULBOUS HEAD PORTION OF APPROXIMATELYELLIPTICAL SHAPE WITH ITS MAJOR AXIS DISPOSED TRANSVERSELY OF THEADJACENT PART OF SAID LEG PORTION AND WITH AN OUTER PORTION EXTENDINGOUTWARDLY FROM SAID LEG IN A DIRECTION AWAY FROM SAID STEM PORTION ANDHAVING A ROUNDED SURFACE OVER WHICH SAID BASE STRIP IS BENT, SAID OUTERPORTION POSITIONING A BODY PORTION OF SAID BASE STRIP AWAY FROM THEOUTER SURFACE OF SAID LEG PORTION TO PROVIDE A PREDETERMINED SPACE FORTHE FREE SLIDING MOVEMENT OF SAID SLIDER.